An Egyptian mummy is carbon-dated and compared with a scroll found in the Dead Sea, which is known to be 2000 years old. The 14C: 12C ratio of the mummy is found to be 2/3 that of the scroll. How old is the mummy?

**Details and Assumptions:**

* 14C is radioactive with a half-life of 6000 years (it decays into nitrogen). 12C is a stable isotope, so the amount of 12C in a sample remains constant over time.

* The ratio 14C:12C in an organism (plant or animal) at the time of its death is equal to the ratio of the isotopes in the air it breathed in. This ratio can be assumed to be constant over time.